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Blazing Speed: The Fastest Stuff In The Universe
Unfallversicherung writes "'If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second. But if you are matter, then it's another matter altogether.' Astronomers are now measuring matter that moves at 99.9 percent of light-speed. Jupiter-sized blobs of hot gas embedded in streams of material ejected from hyperactive galaxies known as blazars."
How about linking to the original Space.com article?
Blazing Speed: The Fastest Stuff in the Universe.
1) Under the current physics, light-speed travel is impossible. As you approach the speed of light, the energy required to accelerate you further approaches infinity.
2) As you accelerate to 99.9% the speed of light, time slows down very significantly. Theoretically, at the speed of light, the passage of time stops, but since you cannot accelerate to the speed of light, that's a moot point.
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Speed measurements in astronomy are usually made by measuring the doppler shift of of the light emitted. If you find the spectrum of for instance Hydrogen (a very common pattern) but the spectral lines are shifted compared to the spectrum of hydrogen on earth. From this you can measure the relative speed between us and the source. This is accurate , hard to distort and relies on only one measurement.
But what exactly is the speed of light? If I stand here and shine a laser, sure, it has a speed, but think about it: This planet is hurtling through space at breakneck speeds. Now add the speed of light from my laser to the speed the Earth is moving, and voila! You have a speed faster than the speed of light
First rule of relativity club is the speed of light is the same for all observers. Which means your laser will appear to be travelling the same speed for somebody travelling through space at "Breakneck speeds" as it would for somebody just leaning back in a chair sipping a Corona watching you.
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Not really, see this is exactly what special relativity explained. The speed of light is constant. If you're moving at 50% of the speed of light, and some light wizzes past you, it looks to you as if it were going at 100% of the speed of light (not 50%). And to an outside observer seeing you go past, it also looks like the light is going at 100% of the speed of light (not 150%). What has happened is that because you are going at 50% of the speed of light, time for you has slowed down, so the if the light goes past at what would apparently be 50% of c if time were not slowed, it still looks to you as if it were going at c.
LOL. Talk about misinformation and hype. It's trivial to transmit an interference wave with a phase velocity faster than the speed of light. That doesn't imply that you can send a signal with information content faster than light - the group velocity (the information carrier or signal you actually control) can't go faster than light.
It's easy to create signals with "phase velocities" faster than the speed of light, for example set up a series of identical oscillators such that the phase of oscillation is perfectly in sync (within a stationary observers frame). Such a system will have an infinite phase velocity, (or within the limits of experimental error it can easily be made greater than c). This phase velocity merely means the phase of the "wave" of the oscillation appears to travel infinitely fast from one oscillator to the next.
But the key point is that no information is transferred faster than the speed of light, and thus everything still adheres to the confines of special relativity. So the parent AC is correct that one can create an effective velocity larger than c, but one cannot do anything useful with it.
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how to add relativistic speeds
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A good post, though it's a little vague for the most of non-science geeks.
Basically, in the relativistic frame, the Newtonian kinetic energy (0.5*mass*velocity^2) is no longer valid. To make "relativistic" correction, it needs to be scaled by the quantity called "gamma", which has the form:
gamma = 1.0/sqrt(1.0-(v/c)^2)
where c = speed of light and v is the motion of an object (here 0.999c). Now the relativistic kinetic energy is scaled by this gamma factor as:
Kinetic Energy = mass * c^2 * (gamma - 1.0).
In this case, v=0.999c, the gamma factor has the value of 22.4. Then for the mass of a Jupiter size planet, the relativistic kinetic energy is about 2e52 erg, which is about 10 supernovae explosion worth of the energy.
Now if you imagine that v=0.9999 (another "9"), then the gamma factor jumps up to 70.7, instead of 22.4. That's what the parent poster meant to say by the "non-linear" term.
The more you know, the better off you are.
As I recall from a late 1990s lecture by Hawking, some matter can exceed "the speed of light" and in doing so, escape a black hole. At an event horizon exactly, that border at which matter including light either escapes a black hole or not, the position of particles is known with complete precision. As such, Heisenberg's Uncertainty Principle dictates that the speed of the particles cannot be known as precisely. Photons at the event horizon of a black hole are allowed, by a tiny quantity, some Scotty Factor in their speed because their position is certain. In plain words, these are the mathematics of the matter :) Some leptonic matter, in only such a particular position, can be slightly faster than "the speed of light."
As theorized, Hawking's predictions that black holes might leak have, I understand, been observed as radiation from what are as-yet assumed to be black holes. Anyone knowing more than I do about this particular phenomenon is (un?)certainly welcome to add more. The explanation Hawking made was directed at interested and able nonprofessionals; he put forward some mathematics around but not specifically deriving the surprising conclusions. Made sense to me, anyhow. I believe the matter discussed here, blasers measured at .999999... of light's speed, is the fastest measured "directly." But I do not believe this is the fastest known matter, if you allow that "knowing" the speed of the matter Hawking discussed (observed as radiation) was theoretical and later indirectly measured.
BG
Observing particles moving at 99.9% c is not so amazing as it sounds. First of all we routinely accelerate matter to great speeds for use in particle physics experiments (in places such as CERN, SLAC, FermiLab, Brookhaven, etc.).
As an example, the LEP accelerator at CERN which was used in the period 1989-2000, acceleratod electrons to about 99.9999999977% c.
But even outside the laboratories we have previously observed even larger speeds. The UHECR (ultra high energy cosmic rays) whose origin is still a mystery seems to consist of protons moving at speeds of 1-1^(-22) = 0.9999999999999999999999 c.
Furthermore, it might seem like we need absurd accuracies in our measurements to discern the numbers from each other. But we don't really - the speed of the particle is practically the same when 0.99c and 0.99999c are compared, but things like the momentum of the particle will still differ wildly. For the curious, the formula is: momentum = m*v/sqrt(1-(v/c)^2).
The speed of light can be given in terms of other fundamental electromagnetic constants (1/sqrt(permeability of vacuum * permittivity of vacuum)), but I suspect that this doesn't really answer your question.
Now, the question does have a less profound answer that is not what you have in mind. A meter is DEFINED as the amount of time that light moves in 1/299792458 seconds, so light moves exactly at 299792458 meters per second. The miles per hour speed is just a conversion factor away.
E = m c^3 Don't drink and derive E = m c^3
Yes, the spectral lines always appear in the same place, relative to other elements, because they are emitted at fixed, known frequencies. By identifying them and seeing how far shifted they are from what they'd be if they were at rest relative to us, you get the doppler shift.
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And read this for a more detailed explanation of the issue.
Well the rest mass of a single star (say the same mass as the sun) is 2x10^33 * (3x10^10)^2 ergs ~ 1.8x10^54 ergs. In this post the energy of these objects is estimated at 2x10^52 ergs, so the rest mass of a single star is 90 times one of these objects, and there are on the order of 10^10 stars per galaxy. So before we even discuss dark matter you'd need a hell of a lot of these objects to have greater energy than just the visible stars in our galaxy.
Doug
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